A simple technique is now available for protection against flood water up to 1.80 meter deep using standard pallets, a metal support and a waterproof geomembrane. Other applications of the patented technique include temporary storage of water, fertiliser, sludge and buld goods. It is also possible to dry out areas covered with shallow water.

Simple and economical
The new technique is based on standard EUR pallets and can hold back water up to 1 metre deep. The inexpensive pallets are designed to withstand heavy loads and are available worldwide. They may be rented or purchased and returned after use. The pallet supports are made of galvanised steel sheet and can be folded together to minimise storage space. They require no special anchorages. Because the pallet is inclined, the support is anchored through friction and pressure on the ground. There is also a certain flexibility in the system since the pallets can be placed in their end or side.

The major advantage of the system is its simplicity. Pallets are available almost everywhere and are quickly assembled with little effort. Only a small space is required for storing the metal supports and plastic membrane. Calculations show that with a barrier height of 1 metre, a single pallet replaces about 1.5 tonnes of sand, i.e. 50 sandbags each weighing 30 kg.

Limited damage to gardens
Assembly and disassembly are simple. No heavy machines are required for erecting the barrier. The relatively light modules, consisting of pallets and pallet supports, cause little damage to lawns and gardens compared with sandbags.

Barrier height
Aqua Barrier can hold back water up to 1 metre deep if the pallets are placed on their ends. If they placed on their sides, the barrier height will be 65 centimetres. A more robust type of pallet support is under development providing a barrier height of 1.80 metres (two pallets placed on their ends).

Quick assembly
Aqua Barrier is assembled by inclining each pallet against its support so that they form a line in the desired direction. The barrier can follow ground contours vertically and horizontally. For 90 degree turns, a triangular module is available which is assebled at the outer or inner corner. One man can easily assemble 200-300 metres in a day.

Sealing
A certain leakage occurs between the pallet membrane and the ground. This can be reduced by placing a small amount of soil or sand along the bottom edge of the membrane. The edge of the membrane can also be pushed into the ground to obtain the best sealing. Leaking water is pumped away by conventional means.

Be safe by being prepared
Pallet supports and membrane must of course be stored locally. Pallets are purchased or rented when there is a warning of rising water. In the case of summer flooding due to heavy rain, contracts with local companies supplying pallets may be sufficient to ensure their availability.

An example
Assume that a section of river bank 300 metres long needs to be protected. There are also ten houses that need to be surrounded by the flood barrier. The length around each house is estimated at 80 metres (20 + 20 + 20 + 20 metres). A barrier height of 95 centimetres is regarded necessary in order to be on the safe side. The barrier must therefore have a total length of 300 + 10 × 80 metres = 1,100 metres, equivalent to 1,375 pallets and supports. Protecting a similar section with sandbags would require about 60,000 sandbags weighing 2,000 tonnes.